How good is it? I sold my 2.8 IS!
I was concerned about the one stop difference between the 2.8 and 4 but what I found was, the IS makes up for it in handhelds and the bokeh is so good that the increased depth of field does not hurt it. One stop for a one pound weight reduction. Equal or better performance. No Brainer!

Another BIG (to me) plus is that it does not attract looky loos and WOW, lookit that lens. Boy, I'll bet that really gets the job done huh? No dildo head, the photographer gets the job done!